Freaks City

Scenario A Docker container exposes a service on a specific port. The goal is to restrict access to this port so that only specific remote hosts are permitted, while all others are denied. Background: Traffic Flow in Docker When Docker runs, it modifies the host's iptables rules. External traffic destined for a container does not pass through t ...

Access Control List Technology Overview Technical Background As networks expand rapidly, security concerns and Quality of Service (QoS) issues become increasingly critical. Access Control Lists (ACLs) serve as an essential technology that enables precise identification of network packet flows. When combined with other technologies, ACLs control ...

FTP Data Transfer Modes Explained File Transfer Protocol (FTP) supports two distinct modes for establishing data connections: Active Mode and Passive Mode. The distinction between these modes is primarily from the perspective of the FTP server initiating or awaiting the data connection. Active Mode FTP In Active Mode, the FTP server actively in ...

iptables Firewall Setup Installing iptables Check current status: systemctl status iptables Stop and disable firewall service: systemctl stop firewalld systemctl disable firewalld Install iptables components: yum install -y iptables iptables-services systemctl start iptables systemctl enable iptables Configuration File Edit the main configur ...

This experiment builds upon previous firewall configurations, expanding functionality with dual-hot standby setup and bandwidth control. For foundational knowledge, refer to prior articles covering NAT and intelligent routing, as well as security policies. Experiment Overview DMZ servers accessible only during office hours (9:00–18:00) by the ...

In modern IT environments, ensuring that access permissions for network services and applications are properly configured is critiacl to maintaining security and operational integrity. Misconfigured or overlapping permissions can lead to policy conflicts, unauthorized data exposure, or service disruptions. A systematic review of access controls ...

Fundamentals of Network Security Auditing Modern network environments require robust auditing of data transmissions to maintain security and regulatory compliance. Effective security management relies on integrating firewall policy orchestration with continuous monitoring of network traffic. Core Technologies for Traffic Control Static Packet F ...

Arch Linux comes with IPv6 enabled by default, so firewall rules must also cover IPv6 traffic. While iptabels and ip6tables are traditional tools, nftables handles both IPv4 and IPv6 through the inet address family or separate ip and ip6 tables. A graphical interface for managing both is firewalld. Basic Firewall Configuration The configurat ...

File Operations: Copy, Move, and Delete In Linux systems, the fundamental commands for file manipulation are cp (copy), mv (move), and rm (remove). ### Copy Command (cp) The cp command follows this syntax: ``` cp [-adfilprsu] source_file destination_file cp [options] source1 source2 source3 ... directory Key parameters include: - `-a`: Archive ...

Core Problem: Hidden Rule Collisions Most production outages that trace back to the firewall are not caused by external attacks but by silently conflicting rules that were never stress-tested together. A typical scenario is two administrators, weeks apart, adding overlapping permits and denies for the same subnet without realizing the interacti ...